Systematical High-Pressure Study of Praseodymium Nitrides in N-Rich Region

【摘要】 We investigate high-pressure phase diagrams of Pr–N compounds by proposing five stable structures （PnmaPr N,Ⅰ4/mmm-PrN₂,C2/m-PrN₃,P■-PrN₄,and R3-PrN₈） and two metastable structures (P■-PrN₆ and P■-PrN₁₀).The P■-PrN₆ with the N₁₄-ring layer and R3-PrN₈ with the N₁₈-ring layer can be quenched to ambient conditions.For the P■-PrN₁₀,the N₂₂-ring layer structure transfers into infinite chains with the pressure quenched to ambient pressure.Remarkably,a novel polynitrogen h R8-N designed by the excision of Pr atoms from R3-PrN₈ is obtained and can be quenched to ambient conditions.The N-rich structures of P■-PrN₆,R3-PrN₈,c-PrN₁₀ and the solid pure nitrogen structure exhibit outstanding properties of energy density and explosive performance.更多还原

【Abstract】 We investigate high-pressure phase diagrams of Pr–N compounds by proposing five stable structures （PnmaPrN,Ⅰ4/mmm-Pr N₂,C2/m-PrN₃,P■-PrN₄,and R3-PrN₈） and two metastable structures P ■(P-PrN₆ and P■-PrN₁₀).The P■-PrN₆ with the N₁₄-ring layer and R3-PrN₈ with the N₁₈-ring layer can be quenched to ambient conditions.For the P■-PrN₁₀,the N₂₂-ring layer structure transfers into infinite chains with the pressure quenched to ambient pressure.Remarkably,a novel polynitrogen h R8-N designed by the excision of Pr atoms from R3-PrN₈ is obtained and can be quenched to ambient conditions.The N-rich structures of P■-PrN₆,R3-PrN₈,c-PrN₁₀ and the solid pure nitrogen structure exhibit outstanding properties of energy density and explosive performance.更多还原